[3H]哇巴因与培养的大鼠血管平滑肌细胞的结合。

[3H]ouabain binding to cultured rat vascular smooth muscle cells.

作者信息

Khalil F, Hopp L, Searle B M, Tokushige A, Tamura H, Kino M, Aviv A

出版信息

Am J Physiol. 1984 May;246(5 Pt 1):C551-7. doi: 10.1152/ajpcell.1984.246.5.C551.

DOI:10.1152/ajpcell.1984.246.5.C551

Abstract

The number of Na+ pump units (Bmax) and the equilibrium dissociation constant (Kd) for ouabain as well as parameters of K+ binding to the Na+ pump were examined in in vitro-grown vascular smooth muscle cells ( VSMC ) derived from Sprague-Dawley rats. The technique to measure these variables utilizes analyses of [3H]ouabain displacement from its VSMC receptors by nonlabeled ouabain and K+. The mean values for Bmax and Kd in the cultured VSMCs were 1.95 X 10(5) receptor sites per single VSMC and 2.68 X 10(-6) M, respectively. The equilibrium dissociation constant for K+ (Ki) was 0.92 mM. K+ binding to the cultured VSMCs demonstrated positive cooperativity with a Hill coefficient (n) of 1.78.

摘要

在源自Sprague-Dawley大鼠的体外培养血管平滑肌细胞（VSMC）中，检测了哇巴因的Na⁺泵单位数量（Bmax）、平衡解离常数（Kd）以及K⁺与Na⁺泵结合的参数。测量这些变量的技术利用非标记哇巴因和K⁺对[³H]哇巴因从其VSMC受体上的置换进行分析。培养的VSMC中Bmax和Kd的平均值分别为每个单个VSMC 1.95×10⁵个受体位点和2.68×10⁻⁶M。K⁺的平衡解离常数（Ki）为0.92 mM。K⁺与培养的VSMC的结合表现出正协同性，希尔系数（n）为1.78。